|My favorite sewing website has two sections on color. One is on Color Harmonies and Color Theory with great color examples as to how the different colors work together.
The other section is on Color Analysis. It's all about what the color choice we pick means (boy did I mangle that). What they explain is, if you prefer blue over red, they tell you what that means - and if you don't like blue, they talk about that too.
I found it very interesting. Plus they always seem to have more information (research, history, beginnings that sort of thing) in the sidebars.
Here are the links:
Color Harmonies and Theory
It might not be something you use everyday, but they're great for reference.